I had the same fear of not knowing if a tire was having pressure problems so I decided to buy the TST system back in 2008. Maybe it was an early system and not perfected but I had awful problems with it.
I never used my tire compressor more than when I had that system on my tires. During that time, I had two sensors go bad and were quickly replaced by customer service. The sensors would cause the tires to lose air. The repeater antenna never worked right for my tow vehicle.
I ended up taking the whole system off and just checked my tire pressures every morning before departure. I could have picked up a nail and had a failure but I was lucky and never had a problem checking them myself.
I gave the system away to someone here on rv.net, I just threw them in a box and mailed them to the guy who said he would take them. A big waste of $500.
Our new coach has the system built-in with the sensors inside the tires.
For those on the Prevost site that I frequent, they all seem to like Pressure Pro.
Safe travels,
MM.